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Diffraction Limit Has Been Beaten
deglr6328 writes "In what is being heralded variously as a "remarkable accomplishment" and a "breakthrough", physicists have reportedly beaten the diffraction limit at optical frequencies. First hypothesized to be possible 30 years ago by Russian physicist Victor Veselago, meta-material "superlenses" with negative refractive indices were first demonstrated around 2001 at microwave frequencies. The use of a thin silver film as an optical superlens in this case, has allowed the team to resolve features less than 40 nanometers wide; 10 times better than any conventional optical microscope. The consequences of the discovery are immediately apparent and include opportunities for extremely fine biomedical imaging in-vivo and greater increases in transistor density for microchips by superlens augmentation of photolithography masks."
http://astrosun2.astro.cornell.edu/academics/cours es/astro201/diff_limit.htm
The calculation shown there is a rough estimate for round openings (hence the 1.22). In essence the resolution of a lense is limited by the wavelength of the light being used and the size of the opening. When the opening is too small, whatever you want to observe is "smudged" due to diffraction effects (the spreading out of waves going through a small aperture). There are two ways to counter this: decrease the wavelength (eg use higher energy light such as xrays) or increase the size of the opening. Both remedies can be problematic since high-frequency light can induce damage and large apertures are sub-obtimal for many applications (especially in semiconductor imaging).